Vehicle to vehicle (V2V) is a current challenge for autonomous vehicles.
V2V communication uses today high frequency (HF) radio communication band (GHz). This frequency allows a very long range and high bandwidth data transmission. Computers included into vehicles can interchange sensor and navigation data by this method.
However, direct localized communication with the vehicles (e.g. cars, trucks, etc.) behind is not effective by using this HF radio communication band. A fast trigger/alarm message communication from front vehicle is not possible.
With low frequency (LF) communication (kHz), one vehicle could send a trigger message to the vehicle behind at very low latencies and high speed. Bandwidth in this type of communications is not big, but enough to transmit alerts or warning messages. LF works like an “intelligent sensor”. It has feedback, i.e. the vehicle sending the message could receive answer from the vehicle behind.
However, communication and reading distances between the systems/devices in a V2V communication must be 20-30 meters, minimum, and to cope with this requirement very long LF antennas are needed.
From patents EP3192084 and EP 3089176, of the same inventors of present invention, elongated flexible low frequency antennas are known. However, these antennas can only work either as a transmitter or as a receiver.
The present invention, therefore, provides a long antenna for LF communication within a vehicle environment including both transmission and reception capabilities within a same magnetic core, and a LF communication system using said antenna integrated in a vehicle, for instance a car.
Main advantages of LF communication are:                Robustness: Low radio frequencies travel through high humidity, cold weather, snow or big storms with no problems. In case of coverage problem on V2V network, LF will continue working.        Cheap: LF frontend electronics is simple and cheap. SOC chipsets are available in the market already. The hardware overhead needed is very small.        Fast: Due to low processing requirements and simple electronics, latency and communication time is really low. Back and forth messages can be resolved in less than 30 ms.        Reliable: Blocking elements (like human bodies, heavy loads, etc.) can't block the signal. Penetration and robustness in the signal is guaranteed.        
LF communication allows a better physical robustness since the wavelength of these signals from 20 to 300 KHz is so long that it is very difficult to shield or attenuate it, so that the meteorological changes and the physical obstacles do not affect as much as the HF or VHF signals.
US 20040252068 discloses a magnetic core antenna system including a magnetic core and a winding network that may be configured with a non-uniform ampere-turn distribution to achieve a desired flux density in the core.